The present invention relates generally to the field of food processing, and more particularly, to hydration of dry materials, which is the process of combining wet and dry ingredients in the production of doughs, batters, and pastes.
In the preparation of doughs for baking or other processing, hydration is followed by the additional steps of mixing the hydrated components into a uniform mass or dough, and further processing as needed to optimize the properties of the dough, depending on the desired finished goods being produced.
In hydration, the dry ingredients commonly include, but are not limited to, flour, yeast, sugar, salt, and the like, and the wet ingredients are generally solutions of water. With mixing and additional processing where needed, the products of hydration are used to form doughs for breads, other baked goods, and pasta, and batters for donuts and other prepared foods as well for less common foods, such as potato chips made from a “dough” of dehydrated potatoes re-hydrated with water or another liquid.
Hydration may be accomplished in batches or by a continuous process. In either case, hydration has commonly been accomplished by mechanically mixing the wet and dry ingredients together using a variety of blades, screws, and other kneading members. For example, in U.S. Pat. No. 3,986,705 (“Nauta”) at FIG. 1, a device for continuously mixing and/or granulating substances includes a generally vertical vessel 1 having an inlet funnel 7a located at the top of the vessel, for admitting dry ingredients. The vessel 1 includes three sets of stirring elements 19, 25, 26 for mechanically mixing the wet and dry ingredients. After three courses of mechanical stirring, the dough leaves the vessel 1 through a lower outlet 12. A motor 9 acts though a transmission 10 to rotate a spindle 11, which extends vertically through the vessel 1. The spindle 11 has a channel 18, which is fluidly connected to a liquid source through an inlet head 32 and a spout 33. A slit 17 is fluidly connected to the channel 18 and discharges liquid from the channel 18 into the vessel 1 to be mixed with the dry ingredients. Located below the slit 17 in a vortex space 3a is a first set of stirring elements 19, which are connected to and are rotated by the spindle 11 to mechanically mix the wet and dry ingredients. Located below the vortex space 3a is a “split-spaced room” 21, which is fluidly connected to and discharges liquid from the channel 18. Located below the split-spaced room 21 is a second vortex space 3b, in which a second set of stirring elements 25 is connected to and rotated by the spindle 11 to mechanically mix the wet and dry ingredients. Located below the second vortex space 3b, near the bottom of the shaft 11, are channels 27 for discharging liquid from the channel 18 into the vessel 1, and a third set of stirring elements 29, connected to and rotated by the spindle 11 for mechanically mixing the wet and dry ingredients. Thus Nauta's device accomplishes hydration through repeated mechanical mixing of the wet and dry ingredients.
Some devices perform continuous hydration processes in which the wet and dry ingredients are combined by spraying a high-pressure liquid stream including the liquid ingredients into a mixing chamber through which the dry ingredients are conveyed or dropped.
For example, U.S. Pat. No. 7,332,190 (“Noll”) discloses devices and methods for dough production. In a horizontal embodiment 12, seen in Noll's FIG. 1, dry ingredients in a flat layer are conveyed by a screw conveyor 10 into a mixing chamber 12, where a nozzle 16 sprays water at high pressure (30 to 100 bar) into the dry ingredients. In some of Noll's embodiments, compressed air is also introduced into the mixing chamber via an air nozzle 18 in order to regulate the incorporation of air into the dough. In a vertical embodiment, seen in Noll's FIG. 3, dry ingredients enter through an inlet section 32, which is a conduit with a generally rectangular cross section, and fall through the device. Below and connected to the inlet section 32 is a mixing chamber 30. Compressed air is introduced into the dry ingredients through an air nozzle 18 in a side wall of the inlet section 32. After the dry ingredients fall down past the air nozzle 18, the dry ingredients reach a slotted nozzle 36, located in a side wall of the mixing chamber 30 and spanning the width of the mixing chamber 30. The slotted nozzle 36 sprays water or other liquid into the dry ingredients at a high pressure (30 to 100 bar). The dry ingredients and the liquid combine to form a dough or paste, which falls to the bottom of the mixing chamber, exiting through a horizontal discharge 34.
The present invention described herein comprises a new hydrator for combining wet and dry ingredients for making dough, batter, pastes, and other food products. The present invention preferably thoroughly combines the wet and dry ingredients without mechanically mixing the wet and dry ingredients together, and without requiring that the wet ingredients be provided at high pressure. Preferably the fan blades and dry blades act on the dry ingredients prior to addition of the wet ingredients, with the wet agreements being added to the dry ingredients after the dry ingredients have fallen below the level of the fan blades and the dry blades, so that the fan blades and the dry blades do not mix or knead the combined liquid and dry ingredients. The present invention thus is different from Nauta, which (as explained in detail above) subjects the dough to courses of mechanical mixing after the wet ingredients have been added to the dry ingredients. The present invention preferably creates a more uniform product than prior devices, and does so more quickly, with less energy use, and with less heating of the ingredients that previous devices. The present invention preferably requires less mechanical energy than prior devices for hydration, resulting in smaller and less costly equipment, better control of temperature, and reduced costs for dough, batter, and paste production.